DE4024311A1 - Imaging laser printer, digital copier or facsimile - shows data relating to working voltage and remaining working life when fixing unit is attached - Google Patents

Abstract

The fixing unit (33), operable in a predetermined drive voltage range, in removably mountable on a part or the housing of the imaging appts.. A unit delivers an output voltage to the fixing unit. Another unit detects or describes the operating voltage of the fixing unit fitted. A control circuit (133) ascertains of the delivered output voltage lies within the designated voltage range. A further unit allows the delivered output voltage to pass to the fixing unit if it does lie within the drive voltage range. A display shows the result, i.e. if the output voltage is within or outside the drive range. The fixing unit has a working life monitoring and fuse unit (174,175,176). The condition of the latter is indicated when the mains switch is switched on. ADVANTAGE - Avoids interference or failure if range of working voltage in relation to input a.c. voltage is falsely set.

Description

The invention relates to an image forming apparatus, e.g. one Laser printer, a digital copier or a facsimile device that with removable, in different operating chip Fixing devices operable in areas units can be equipped.

A fuser for thermally fusing a developer The picture on a sheet of paper is usually in one Copier or the like built-in. The fuser must be out be changed if a copy number of e.g. 80,000 er is enough. It can also be due to a malfunction or the like prove to be necessary, even a photosensitive or photoconductor drum or a developing unit switch.

For this reason, in a conventional picture such as a laser printer, a photosensitive Element, a development unit and a fuser designed as separate module units (cartridge units), which can be easily installed and removed.

With such a device, an AC input voltage appropriately turned on for different fuser units poses. The range of operating voltages is switchable. For example, in Japan, an AC input voltage of 100 V / 50 Hz used, while in North America one of 115 V / 60 Hz and in Europe of 220 V / 50 Hz to be used. In the case of the AC input voltage of 100 V is a range of operating voltage 80-120 V. In the case of the AC input voltage of 115 V, as in North America, this range is 96-144 V. In case of AC input voltage of 220 V (Europe) the operating voltage range is 176-288 V.  

In the event that a user accidentally enters the wrong operating chip the following two problems occur:

• 1. If the input voltage is below the target range of Operating voltage is (input voltage <range of Operating voltage), the temperature can be not reach the intended size; This can an inadequate fixation or a malfunction of a switch result in power supply.
• 2. If the input voltage is above the target range the operating voltage (input voltage <range the operating voltage), the fuser can Blower, a power supply or the like. to be damaged or melt through.

The only countermeasure for the second problem is providing one with an AC input line fuse connected in series. Such enamel fuses have different characteristics, and it takes a long time for them to melt span. As a result, one of the fuses can follow switched fuser or the like. (nevertheless) be damaged.

In the case of the former problem, no sub occurs Breaking of a fuse, i.e. a protection direction does not respond. In particular a switching (type) power supply (switching type power source) is for the Generation or delivery of a predetermined output chip voltage even when the input AC current is low sets. As a result, a switching transistor can be overloaded and be damaged by it.

With the specified device, a malfunction or a failure occur when the range of operating voltage  not correct in relation to the AC input voltage is set or specified.

The object of the invention is therefore to create an image generating device in which a malfunction or failure can be avoided if the area of the company chip voltage in relation to an input AC voltage is incorrectly set or set.

The invention relates to an image forming apparatus which by a power source or supply for an image Generation can be activated and the one fuser unit Freeze a developer image on a recording carrier (developing sheet), the fixing unit in a certain range of operating voltage drivable and removable on the body (housing) of the device brought, comprising: an output unit for outputting an output voltage from the power supply, a loading drawing unit for designating the Be range of the operating voltage of the fusing unit, a loading mood unit for determining whether the output voltage from the output unit within the unit designated (or predetermined) range of Operating voltage is, and a supply or delivery unit for supplying or supplying the output voltage of the output unit to the fuser when the loading has determined (determined) that the Output voltage within the designated range of Operating voltage is.

The invention also relates to a current Supply for the generation of images that can be activated device on which a (certain) area of the Fusing unit with operating voltage detachably attached brought, comprising: an output unit for output  an output voltage from the power supply, a loading Drawing unit for designating (or specifying) the designation range of operating voltage for the fuser, one Determination unit for determining whether the output voltage from the output unit within the unit designated range of the operating voltage is a feed or delivery unit for feeding or Deliver the output voltage from the output unit to the Fuser unit when the determination unit is determined has that the output voltage within the designated Range of the operating voltage, and a display on unit to display the determination result.

In such an image forming apparatus for generating an Image and in which a range of operating voltage having fixing unit is removably attached, there the output unit from a power supply voltage, be the designation unit draws the area of operation voltage of the fusing unit and a determination is made, whether the output voltage from the output unit inside of the area designated by the designation unit the operating voltage.

Furthermore, the off with this image forming device output voltage from the output unit of the fusing unit supplied when the output voltage is as designated in Range of operating voltage determined horizontally (or is determined).

In addition, this imaging device is used shows that the output voltage is outside the (designated) Range of operating voltage is when the output voltage as outside the designated range of loading drive voltage is determined lying.  

In addition, such an image forming device is used shown that the output voltage is below the range the operating voltage is when the output voltage is as below the operating voltage range is set, or it is displayed that the output voltage is above the operating voltage range, if the output voltage is above the range of Operating voltage is determined lying.

The following is a preferred embodiment of the Er Finding explained in more detail with reference to the drawing. Show it:

Fig. 1 is a block diagram showing the whole configuration of an image forming apparatus according to the invention,

Fig. 2 is a perspective (perspective) view of the outer appearance of the image forming apparatus,

Fig. 3 is a vertical section view Seitenan held in the image forming apparatus,

Fig. 4 is a held in an enlarged scale and in vertical sectional side view of the device generating images,

Fig. 5 is a perspective view of the Bilderzeu supply device in the event that his (s) is open upper side (r) lid or cover,

Fig. 6 processing a representation of the connection between the Ge councils body (housings), and a Wechselstromlei,

Fig. 7 is a perspective view of the embodiment of the alternating current or power line (AC power cord),

Fig. 8 is a view of the rear of the apparatus body,

Fig. 9 is a circuit diagram showing the feeding in an input AC voltage to a heater (ele ment) lamp,

Fig. 10 is a circuit diagram of a directional over-voltage protection from,

Fig. 11 is a table showing the ON / OFF state of a display (unit), the ranges of operating voltages and the ON / OFF state of a bidirectional thyristor in relation to the switching position of the input voltage in order switch,

Fig. 12 is a graph of signal wave forms in a substantial part of the surge protection device,

Fig. 13 and 14 are views of a fixing unit provided at the bottom of the connector part,

Fig. 15 is a diagram illustrating of fuses in the fixing unit and a fuse discriminating circuit,

Fig. 16 is a tabular view for explaining a method for discriminating a voltage specification for explaining the fuser and

Fig. 17 is a flowchart for an initiation or start operation when turning on the power supply.

Fig. 1 shows a block diagram of the overall structure of an electrophotographic image generating device according to the invention using a semiconductor laser. Fig. 2 illustrates the imaging device schaubild Lich, while Fig. 3 illustrates in vertical section the internal structure of the imaging device. Referring to FIG. 1, the image forming apparatus (laser printer) of an auxiliary system 131 or an external device, eg a computer or word processor elec tronic, supply control unit via a Übertra as an interface (nschaltung) 132 connected. Upon receipt of a print start signal from the auxiliary system 131 , the image forming apparatus starts an image recording operation for recording an image on a paper sheet serving as a recording medium.

The structure of the image forming device is explained in more detail below with reference to FIGS. 2 to 5.

According to Fig. 3 in the middle region of an apparatus body or case 1, a main control board 2 is provided on the rear side (on the right side of FIG. 3) an elec trophotographische process unit 3 is arranged for imaging at. A control board receiving unit 5 for receiving a number of additional function control boards 4 is arranged in a lower front region of the body or housing 1 . A sheet discharge unit 6 is provided in the upper front area of the body 1 .

Depending on the functions to be added (e.g. font, number of Chinese characters, etc.), a maximum of three additional function control boards 4 can be used. Additional functions can be added by means of additional function IC cards 17 , which can be inserted into three IC card connectors 16 on the front edge of the lowermost additional function control board 4 . Furthermore, two interface connectors, not shown, are provided on the left end face of the lowermost additional function control board 4 . The latter face an opening 18 (see FIG. 2) formed in the left side surface part of the device body 1 .

The lower part of the device body 1 serves as a cassette container 8 for receiving a sheet or paper cassette 7th

Referring to FIG. 2, the leaf or paper discharge unit 6 is formed in a recess in the upper end face of the body 1. With the front edge of the paper discharge unit 6 , a foldable paper discharge compartment 9 is coupled. In the central region of the front edge of the discharge compartment 9 , a recess 9 a is formed. From the savings 9 a there is a rotatably held, an angular profile possessing paper auxiliary discharge compartment 10 , which can be opened according to FIG. 3. The size of the paper discharge unit 6 can thus be adjusted according to the size or format of the respective paper sheets P who.

On an upper side of a left frame part 1 a of the body 1 , ie on the left side of the discharge unit 6 , an operating panel 14 is arranged, which has a light-emitting diode or LED display unit 11 , a two-digit 7-segment display unit 12 for displaying operating states and has a switch 13 . On the back of the body 1 , a hand input compartment 15 is attached.

The following is reference to FIGS. 3 and 4, the load electrophotographic process unit 3 to perform elec trophotographischen processes, such as electrostatic on, strip exposure, development, image transfer, paper-and-down, cleaning and fixing described.

In a central region of an element space, a drum-shaped photosensitive element 20 , which serves as an image receiving element, is referred to as the (photoconductor) drum. Around the (photoconductor) drum 20 are an electrostatic charging unit 21 formed by a scorotron, an exposure part 22 a of a laser exposure unit 22 , which serves as an electrostatic latent imaging unit, a magnetic brush development unit 23 , which development and cleaning steps at the same time, a transfer charger 24 constituted by a scorotron, an after-image removing brush 25 and a pre-exposure lamp 26 are arranged; these components are arranged in the specified order in the direction of rotation of the drum 20 .

In the device body 1 , a paper transport path 29 is seen before. A paper sheet P drawn from the paper cassette 7 via a paper feed unit 27 or a paper sheet P entered via the manual input compartment 15 runs over this transport path 29 . In particular, the paper sheet P passes an image transfer station 28 between the drum 20 and the transfer charging unit 24 , in order to then reach the paper discharge unit 6 on the upper side of the device body 1 .

On the upstream side of the image transfer station 28 , two transport rollers 30 , two alignment rollers 31 and two further transport rollers 32 are arranged on the paper transport path 29 . The image transfer station 28 are a fixing unit 33 and a paper discharge unit 34 downstream. About the transport rollers 32 be a cooling fan unit 35 .

In the vicinity of the alignment rollers 31 , an alignment switch 36 is provided, while a transmission guide 37 is arranged near the image transfer station 28 .

When the image forming apparatus receives a print start signal from the auxiliary system 131 , the photosensitive or photoconductor drum 20 is rotated and electrically charged. Then, image data supplied by the auxiliary system 31 are modulated into a laser beam a. The Laserbe lighting unit 22 allows the laser beam a to scan and expose the drum 20 . In this way, an electrostatic latent image corresponding to the image signal is generated on the drum 20 . The on the drum 20 he created electrostatic latent image (or charge image) is developed by means of the toner t, which is contained in a developer magnetic brush D 'of the development unit 23 .

In synchronism with the generation of the toner image, the paper sheet P fed from the cassette 7 or via the manual input compartment 15 passes through the alignment rollers 31 . Due to the action of the transfer charger 24 , the toner image formed on the drum 20 is transferred to the paper sheet P. Then the paper sheet P passes through the paper transport path 29 to enter the fixing unit 33 . In the latter, the toner image is melted and fixed on the paper sheet P. The paper sheet P is then discharged through the paper discharge roller unit 34 to the paper discharge unit 6 .

The toner remaining after the transfer of the toner image onto the paper sheet P on the photoconductor drum 20 is removed by the after-image removal brush (memory removal brush) 25 consisting of an electrically conductive brush. This eliminates after-image or residual developer.

According to FIG. 4, the fixing unit 33 includes a heating roller 41, is housed in which a Heizelementlampe or lamp heater 40 and a heating roller 41 at the pressing roller 42nd When the paper sheet P passes between the rollers 41 and 42 , the toner image is melted and fixed on the paper sheet P.

The heating roller 41 and the pressure roller 42 are closed by a lower housing part 43 and an upper housing part 44 , whereby an appropriate fixing temperature is maintained and heat leakage to the outside is prevented.

A cleaning unit 45 is in constant contact with the heating roller 41 in order to keep it clean and in a suitable fixing state. A thermistor 46 is provided to maintain a temperature required for fixing.

In the upper housing part 44 and on the upstream side of a contact area 47 between the heating roller 41 and pressure roller 42 , a paper guide 48 is arranged, which serves to tip or front portion of the paper sheet P, which has entered the fixing unit 33 , securely between the heating roller 41 and the pressure roller 42 to guide. Another paper guide 49 formed with the same material as the lower housing part 43 is arranged on the discharge side of the fixing unit 33 . The paper sheet P on which the toner image has been fixed is then fed to the paper discharge roller unit 34 .

The transfer guide 37 , which is connected to the transfer charging unit 24 and leads the non-image side of the paper sheet P, is connected to ground and is used for electrostatically attracting and lifting the paper sheet P.

The paper discharge roller unit 34 includes a lower roller 50 and an upper roller 51 . The unit 34 is followed by a charge removing brush 52, which communicates with the image area of the paper sheet P in contact or con tact. As well as the transfer guide 37 and the transfer charger 24 of the upper part of the unit 34 is mounted häuses 1 with upper roller 51 and charge-clearing brush 52 with an upper cover 60 of the Gerätege.

Referring to FIG. 5, the upper cover 40 is rotatable around a support axis 61 around a maximum of 120 °, which is arranged in the upper back part of the apparatus body 1 direct. If necessary, the majority of the paper transport route 29 can thus be exposed, and the devices facing the transport route 29 can also be exposed or made accessible. This feature facilitates the removal of a stuck paper sheet P, the maintenance of the device and the replacement of parts. In FIG. 5, with an ozone filter 62, and designated by 63 is a toner cartridge.

A rear cover 64 of the device body 1 according to FIG. 3 can be opened or opened by rotating it around a supporting axis 65 . Thus, the initial part of the paper transport path 29 , ie the ge curved transport path part for guiding the paper sheet P from the feed unit 27 , can be opened for easy removal of a stuck paper sheet P.

Referring to FIG. 5, the fixing unit 33 can be taken out 60 with an open upper cover, or be removed. Referring to FIGS. 13 and 14 unit at the bottom of the fixing 33, a connector unit 172 mounted to be described control circuit 133 is even closer electrically connectable to one and the tap with Einsteckleit 170 and a protective plate is provided 171, which in turn has a greater width and has a greater height than the connector unit 172 and serves to protect the latter from damage. The Connector 172 includes connector connections 172 a and 172 b. The connection 172 a is connected to the heating lamp 40 in the fixing unit 33 and a thermal fuse, not shown. The connection 172 a has a large surface area because a current of 10 A (through it) flows at an input AC voltage of 100 V. The connector 172 b is connected to the 33 arranged in the Fixierein thermistor 46 and still to be described fuses 174-176 . The connection 172 b has a smaller surface than the connection 172 a, because the current flowing through it is (only) 1-300 mA.

According to FIG. 4, the laser exposure unit 22 includes a through a polygonal mirror 91 and a mirror motor 92 Polygonalabtaster formed 93, a first and a second f-lens 94 and 95 as well as reflection or deflection mirrors 96 and 97, the laser beam A is a predetermined area to be painted over.

A control board 101 of the laser exposure unit 22 is connected to the main control board 2 via a connector 102 .

The laser exposure unit 22 is accommodated in a synthetic resin housing 103 with a bottom opening which is closed by a metal shielding plate 104 . On the top of the housing 103 , a metal reinforcing shield cover 105 is formed, to which an electrically conductive contact portion or part 106 is connected. When the laser exposure unit 22 is installed in a predetermined position with the aid of fasteners (not shown), the contact part 106 is in (electrical) contact with a metal guide rail for the displaceable guidance of the development unit. The inner components are thus protected from electrostatic interference by the electrostatic charging unit 21 ; this prevents interference with the internal components.

The light-sensitive element or the photoconductor drum 20 is formed from an organic photoconductor material and formed so that a charge generation layer is provided on the outer surface of an aluminum cylinder, which is coated with a charge transport layer.

The development unit 23 works according to a reversal development method to simplify the electrophotographic process and also according to a method for simultaneously carrying out the removal of residual toner and the development. According to Fig. 4, the developing unit 23 has a housing having a developer container 120. In the housing 121 , a development roller 122 of the photoconductor drum 20 is arranged facing. The developer container 120 contains a two-component developer D consisting of a toner (color powder) t and a carrier (magnetic powder) c. A doctor blade 124 for limiting the thickness of a developer magnetic brush D 'produced on the outer surface of the development roller 123 is at a contact portion between this magnetic brush D' and the photoconductor drum 20 , ie on the upstream side of a development position 123 in the direction of rotation of the drum 20 , arranged. The developer container 120 contains first and second developer stirrers 125 and 126, respectively. Serving as a delivery device or Tonerzu führ- toner cartridge 63 (see. Fig. 5) is set so incorporated in the developing unit 23 as to the toner t expedient ter supplies the Entwicklerbehäl 120th

The development roller 122 comprises a magnetic roller 130 with three magnetic poles 127-129 and a non-magnetic sleeve 131 which is placed over the magnetic roller 130 and can be rotated clockwise as shown in FIG. 4. Of the three magnetic poles 127 , 128 and 129 of the magnetic roller 130 , the magnetic pole 128 facing the development position 123 is an N pole, while the other poles 127 and 128 are S poles. The angle 8 between the magnetic poles 127 and 128 is 150 ° (see FIG. 4), while the angle 8 between the magnetic poles 128 and 129 has a size of 120 ° (see FIG. 4). When developing the electrostatic latent image on the photoconductor drum 20 , the residual toner t is simultaneously removed mechanically and electrically, by means of the mechanical removal force due to the magnetic brush development using the two-component developer D and by the potential difference between the charging potential in the reverse development and the to the magnetic brush D 'applied bias potential.

According to Fig. 5 23, the developing unit is a process cartridge (-Moduleinheit) 85, into which the photoconductor drum 20, the electrostatic charger 21 and the Nachbildbeseitigungsbürste are installed 25 and which can be inserted into the apparatus body 1 and taken out of it ent . On the top of the process cartridge 85 , a cleaning brush 144 for cleaning the lower roller 31 a of the alignment rollers 31 is mounted or stored.

A rear side 1 a of the apparatus body 1 according to FIGS. 6 and 8 with an alternating current or power switch 68, a plug-in socket part (socket) 69 for connection to a plug part (pin) 57 of an AC or Netzlei processing 66 (Fig see. 7) to an input voltage switch 70, a green indicator 71, and a red indicator 72 ver. Green and red displays 71 and 72 are switched on, ie activated, by an overvoltage protection device 161 to be described in more detail. The plug-socket part (socket) 69 is designed so that its actuating part is not exposed, even if it is separated from the connector part (plug pin) 57 , while the plug of the power line 66 is connected to a power socket. The green display 71 is switched on or lights up when the input AC voltage lies within the (intended) range of the operating voltage; the red indicator 72 turns on when the AC input voltage is an overvoltage exceeding the operating voltage range. The displays 71 and 72 thus show the user whether the input voltage is appropriate or not. The input voltage changeover switch 70 is operated in accordance with the operating voltage of the image forming apparatus so as to designate the range of the operating voltage adapted to the input voltage. When using the device in Japan, for example, its operating voltage is set to 100 V; in North America it is set to 115 V and in Europe to 220 V.

The operating voltage range is 80-120% of the input voltage. On the basis of this area, the displays are switched on and off, and a bidirectional thyristor 182 to be described for overvoltage protection is also switched on / off. In the case of the input voltage of 220 V intended for Europe, however, the operating voltage range is set to a size between 80% of 220 V and 120% of 240 V in accordance with the normal requirements in Great Britain and on the continent.

For example, assume that the input voltage changeover switch 70 is set to 100 V in FIG. 11. If the AC input voltage is less than 80 V, the green and red displays 71 and 72 and also the bidirectional thyristor 182 are switched off (OFF). If the AC input voltage is between 80 V and 120 V, the green display 71 and the bidirectional thyristor 182 are switched on, ie activated. If the input AC voltage is higher than 120 V, green and red displays 71 and 72 are activated and the bidirectional thyristor 182 is deactivated, ie switched off.

In the following it is assumed that the input voltage changeover switch 70 is set to 120 V. When the AC input voltage is less than 96 V, both the green and red displays 71 and 72 are deactivated, and the bidirectional thyristor 182 is also deactivated. When the AC input voltage is between 96 V and 144 V, the green display 71 and the bidirectional thyristor 182 are activated (switched on). When the AC input voltage is more than 144 V, both indicators 71 and 72 are activated while the bidirectional thyristor 182 is deactivated. It is now more assumed that the input voltage switch 70 is set to 220 volts. In this case, if the input AC voltage is lower than 176 V, the green and red displays 71 and 72 and the bidirectional thyristor 182 are deactivated. When the AC input voltage is between 176 V and 288 V, the green display 71 and the thyristor 182 are activated. When the AC input voltage is higher than 288 V, green and red indicators 71 and 72 are activated while thyristor 182 is deactivated.

The control system of the image forming apparatus will now be described with reference to the block diagram of FIG. 1. As mentioned, the external device (auxiliary system) 131 is electrically connected to the image forming device via the interface 132 . The external device (auxiliary system) 131 is, for example, an electronic computer, a word processor or an image processing device.

The following interface signals are input and output at interface 132 . A signal IVCLKO is a clock signal output from the image forming device to the external device 133 . In synchronism with the clock signal, the external device 131 supplies 8-bit image data IVDAT 70 to 00 to the interface 132 . A signal IHSYNG is a horizontal synchronizing signal which is output from the image forming device to the external device 131 before the transmission of image data for a single scan. Signals IDAT 71 to 01 are signals that flow over a bidirectional 8-bit data bus. Commands (command signals) are output via the bus from the external device 131 to the interface 132 , while status signals are also output to the external device 131 via the bus, which signals are representative of the status (operating state) of the image-forming device. An IDSTAO signal is used to determine the direction of data transfer via the 8-bit data bus. A signal ISTBO is a strobe signal, which enables the image generating device to receive commands. The two signals IDSTAO and ISTBO are output by the external device 131 . An IBSYO signal is a busy signal indicating that the imaging device is processing commands from the external device 131 . A signal IATN 1 is a warning or notification signal that is emitted by the image-forming device when a situation has occurred in the image-forming device that is to be reported to the external device 131 immediately. An IPRDYP signal indicates that the imaging device is in a ready state. A signal IPRIMEO is a reset signal output or supplied from the external device 131 to the image forming device. A signal ISCLR 1 is a delete or release signal to be output from the image-forming device to the external device 131 and is supplied when the device is switched on or off.

The signals fed to the image forming device via the interface 132 are fed to a control circuit 133 and an image signal processing circuit 137 .

The control circuit 133 includes a microcomputer and its peripheral circuitry, and it processes various data and performs various controls. The main functions of the control circuit 133 are given below:

• 1. The control circuit 133 decodes the data supplied from the interface 132 , that is, a command from the external device 131 . In accordance with this command, the control circuit 133 controls various parts or components of the device. The circuit 133 outputs data for the status according to the command to the external device 131 via the interface 132 . In addition, the control circuit 133 controls the output of the signals IATN1, IPRDYO and ISCLR 1 .
• 2. The control circuit 133 outputs data for a display content to a display circuit 134 for driving the LED display unit 11 and the 7-segment display unit 12 on the operation panel 14 .
• 3. The control circuit 133 causes various solenoids 135 to be switched on and off.
• 4. The control circuit 133 receives and processes data from various switches 136 .
• 5. The control circuit 133 sets various scheme or pattern data in the image signal processing circuit 137 and outputs internally generated pattern data to this circuit 137 .
• 6. The control circuit 133 enables a mirror motor / laser driver circuit 138 to activate / deactivate a mirror motor 92 and effects the setting and monitoring of the energy (current) to produce a laser beam emission.
• 7. Control circuit 133 causes LEDs on and off in toner density sensors 143 and 144 , and processes the toner density data provided by sensors 143 and 144 .
• 8. The control circuit 133 controls a high voltage power source 145 . In particular, it causes the electrostatic charging unit 21 to be switched on and off and the setting of the power to be supplied to the charging unit 21 ; switching on / off a charging grid 140 and adjusting the energy to be supplied to the latter; turning on / off the transfer charger 24 and the power to be supplied thereto; turning on / off a transmission grid 139 and adjusting the power to be supplied thereto; turning on / off a developing biasing member and adjusting the power to be fed thereto and turning on / off the after-image removing brush 25 and adjusting the power to be fed thereto. The control circuit 133 also monitors the respective output power.
• 9. The control circuit 133 causes a main motor 150 to be switched on and off and monitors the normal rotation thereof.
• 10. The control circuit 133 turns a blower motor 151 on and off.
• 11. The control circuit 133 turns the pre-exposure lamp 26 on and off.
• 12. The control circuit 133 monitors the temperature of the heating roller 41 of the fixing unit 33 and actuates a driver 152, formed by an inverter and an npn transistor (not shown), for switching a solid-state relay (SSR) 165 , in order thereby to switch the heating lamp 40 on and off .
• 13. The control circuit 133 determines whether the Fixierein integrated 33 new or older is, monitors the operation lifetime of the fuser 33, the end of the service life determines the fixing unit 33 and be true the voltage specifications or specifications of the 100 V series and the 200 V series based on the states of two fuses provided in the fixing unit 33 and the count of a memory 153 .
• 14. The control circuit 133 determines whether the voltage supply for the imaging device, which is selected by means of the input voltage switch 70 with 100 V, 120 V or 220 V, is adapted to the voltage specification of the fixing unit 33 , which fuses in by the fuses the fixing unit 33 is determined.

As indicated above, the control circuit 133 serves as an instruction unit for the image forming apparatus.

The heating (element) lamp 40 of the fixing unit 33 is supplied with an input AC voltage from an AC or mains source, not shown, via the mains line 66 , the plug-in units 57 and 59 , a circuit breaker 160 , the mains switch 68 , the overvoltage protection device 161 , the changeover switch 164 , the solid state relay (SSR) 165 and a thermal fuse 166 fed. The high-voltage source 145 connected to the downstream stage of the overvoltage protection circuit 161 is likewise fed with the input AC voltage by the mains current source. The blower motor 161 downstream of the changeover switch 164 is also supplied with the same voltage.

The overvoltage protection device 161 is connected downstream of the network switch 68 . If the AC input voltage is lower than the operating voltage range (low voltage) or higher than the operating voltage range (overvoltage), the overvoltage protection device 161 prevents the input AC voltage from being applied to its downstream stage, thereby causing the green and red indicators 71 to be switched on / off or 72 . The overvoltage protection device 161 comprises an overvoltage protection circuit 162 and an internal circuit 163 of the bidirectional overvoltage protection thyristor 182 . Referring to FIG. 10, this circuit 162 includes a full-away rectifier diode stack 180, a protective resistor R1 for voltage reduction, a changeover switch to the input voltage coupled to 70-actuated switch 181, zener diodes D 1, D 2 and D 3 for voltage reduction for the Umschal ter 181 , a Zener diode D 4 for Zener clamp (capacitors), capacitors C 1 and C 2 , a smoothing circuit 183 formed by a resistor R 2 , voltage dividing resistors R 3 , R 4 and R 5 , an npn transistor T 1 , resistors R 7 and R 8 , the green display 71 , the red display 72 and a light-emitting diode D 5 . The internal circuit 163 comprises as shown in FIG. 10 is a photothyristor D 6 forming a photocoupler together with the light emitting diode D 5, a resistor R10, an NPN transistor T2, voltage dividing resistors R 11, R 12, R 13 and R 14 , a protective resistor R 15 , diodes D 7 , D 8 , D 9 and D 10 , capacitors C 3 , C 4 and C 5 and resistors R 15 , R 16 and R 17 .

When the power switch 68 is closed and the AC input voltage is fed within the operating voltage range, which corresponds to the position of the input voltage changeover switch 70 , this input AC voltage is subjected to full-wave rectification by the diode stack 180 . The rectified voltage is reduced by the protective resistor R 1 and fed to the Zener diodes D 1- D 3 . The changeover switch 181 is actuated depending on the position of the input voltage changeover switch 70 . After the decrease (after dropped) by the Zener diodes D 1- D 4 , the input AC voltage is smoothed by the capacitor C 1 , the resistor R 2 and the capacitor C 2 and applied to the resistors R 3 , R 4 and R 5 . The waveforms of the voltage up to this state are shown in Fig. 12. Fig. 12 (a) shows the waveform of the AC input voltage from the power line 66 ; Fig. 12 (b) shows the waveform of the full-wave rectified voltage output from the diode stack 180 ; Fig. 12 (c) illustrates the wave form of the voltage after the Zener clipping as it is output at the cathode of the Zener diode D 4 ; and Fig. 12 (d) illustrates the voltage waveform after capacitor smoothing as output from capacitor C 2 and applied to resistor R 3 , red indicator 72, and resistor R 8 .

The voltage divided by the resistors R 3 and R 4 is impressed on the resistor R 5 and the transistor T 1 . However, this voltage is lower than the threshold value of transistor T 1 , so that it does not turn on. As a result, the red display 72 is not switched on or activated. The light-emitting diode D 5 is switched on or activated by the voltage emitted by the resistor R 8 , the light emitted by the light-emitting diode D 5 falling on the photothyristor D 6 . On the other hand, a voltage output by the resistor R 7 drives the green display 71 . This is activated (lights up) to inform the user that the AC input voltage is appropriate. The light emitting diode D 5 and the photothyristor D 6 form the photocoupler.

In the internal circuit 163 , the resistor R 17 and the capacitor C 5 are connected in parallel with the bidirectional thyristor 182 in order to absorb the interference signals of this thyristor 182 connected in series with the input alternating current or mains line. The capacitors C 3 and C 4 and the resistor R 16 serve to absorb interference signals from a gate or gate G of the bi-directional thyristor 182 . When such an AC input voltage is fed in that the voltage on the side of the anode (A) of the thyristor 182 is greater than the voltage on the side of its cathode (K), a voltage is applied to the diode D 7 via the protective resistor R 15 , which then switches on while the diode D 8 blocks. The voltage from the diode D 7 is impressed through the resistor R 14 to the voltage-dividing resistors R 12 , R 11 and R 13 . Since the AC input voltage has a sine waveform, the initial part of the divided voltage is below the threshold value of the transistor T 2 , so that it blocks. If at this time the light-emitting diode D 5 is switched on and the light emitted by it falls on the photothyristor D 6 , the latter switches through. In this case, the input AC voltage is applied via the diode D 10 to the gate or gate G of the bidirectional thyristor 182 , so that this thyristor 182 turns on. When the input AC voltage rises in accordance with the sine curve, the threshold level of transistor T 2 is impressed on transistor T 2 via increasing divided voltage, so that it switches on. According to the sine curve of the AC input voltage, the transistor T 2 is switched on and off alternately. Even if light falls on the photothyristor D 6 , it is only blocked or switched off when the transistor T 2 is blocked, ie at the zero crossing point of the AC input voltage. As a result, the bidirectional thyristor 182 is turned on or activated at the zero crossing time.

When such an AC input voltage is supplied that the voltage on the anode side (A) of the bidirectional thyristor 182 is lower than the voltage on the cathode (K) side thereof, the voltage on the cathode K and gate G of the thyristor 182 becomes on as well the diode D 9 applied . Similar to the case described above, the bidirectional thyristor 182 only turns on when the AC input voltage is at the zero crossing point and light falls on the photothyristor D 6 .

When the AC input voltage falls within the operating voltage range as described above, the bidirectional thyristor 182 turns on at the zero crossing time and the voltage is applied to the heater lamp 40 , the high voltage source 145 , the blower motor 151 , etc. Since the bidirectional thyristor 182 switches through at the zero crossing time, the generation of a surge current due to a capacitor load in the high-voltage source 145 and a lamp load in the heating lamp 40 can be avoided.

If the input AC voltage is below the operating voltage range, the Zener diodes D 1- D 3 and also the light-emitting diode D 5 are not switched through or activated, and the photothyristor D 6 is blocked. Accordingly, the bidirectional thyristor 182 is blocked. Thus, if the AC input voltage is a (too) low voltage, no voltage is applied to heater lamp 40 , high voltage source 145 , blower motor 151 , etc. In this way, interference with the switching power source or supply due to low voltage operation can be avoided.

On the other hand, if the AC input voltage is above the operating voltage range ("overvoltage state"), the diode D 5 and the green display 71 are activated, as is the case even when the AC input voltage is within the operating voltage range. In this case, however, the divided voltage supplied by the resistors R 3 and R 4 exceeds the threshold level of the transistor T 1 , so that the transistor T 1 switches through and the red indicator 72 is activated. On the other hand, the light emitting diode D 5 and the bidirectional thyristor 182 are switched off or blocked. If the input AC voltage represents an overvoltage, no voltage is therefore applied to the heating lamp 40 , the high-voltage source 145 , the blower motor 151 , etc. This prevents thermal destruction of the heating lamp 40 due to the overvoltage. In this case, both the green and the red displays 71 and 72 are activated in order to inform the user of the presence of an overvoltage.

If the light-emitting diode D 5 and the photothyristor D 6 are optically coupled to one another via an optical fiber strand, the overvoltage protection circuit 162 and the internal circuit 163 can be arranged separately. Since the internal circuit 163 is used to switch a large current, the wiring or line impedance must be lowered. If light-emitting diode D 5 and photothyristor D 6 are optically connected to one another and electrically separated from one another, the wiring or line impedance in the overvoltage protection circuit 162 need not be reduced.

Referring to FIG. 15, the fixing unit 33 includes a fuse 174 for detecting or determining the end of the service life of a unit or a device of the 100 V series, a fuse 175 for detecting the end of the service life of a device of the 200 V series and a fuse 176 to discriminate a new from an old development unit. The fuses 174 and 176 are or are specifically connected to a new fusing unit 33 of the 100 V series or the 120 V series, while the fuses 175 and 176 are connected to a new fusing unit 33 of the 200 V series . These fuses are connected via the connector 172 b to a fuse determination circuit 173 , which in turn is connected to the control circuit 133 and is controlled by the latter to confirm the respective state of the fuses 174 , 175 and 176 and to interrupt the circuit leave (break them).

The fuse determination circuit 173 comprises in verter 191 , 195 and 196 , buffers 192 , 193 and 194 , npn transistors Ta, Tb and Tc, resistors R 20 , R 21 , R 22 and R 23 and diodes D 11 , D 12 , D 13 , D 14 , D 15 and D 16 . For example, when the control circuit 133 turns on the transistor Tb, it determines that the fuse 176 is connected when a low level signal is output from the buffer 194 , and determines an open or blown fuse 176 when the buffer 194 outputs a high level signal. On the other hand, when the control circuit 133 turns on the transistor Tc, it determines that the fuse 174 is closed when the buffer 192 outputs a low level signal, and it determines when a high level signal is output from the buffer 192 that the fuse 174 is broken. In this case, the control circuit 133 further determines that the fuse 175 is closed when the buffer 193 outputs a low level signal and determines an interruption of the fuse 175 when a high level signal is output from the buffer 193 .

When the control circuit 133 turns on the transistors Ta and Tb, a current source current of +24 V flows through the resistor R 20 , the transistor Ta, the diode D 12 , the fuse 175 and the transistor Tb, whereby the fuse 176 is interrupted. On the other hand, when the control circuit 133 turns on the transistors Ta and Tc, a current source current of +24 V flows through the resistor R 20 , the transistor Ta, the diode D 13 , the fuse 175 and the transistor Tc, whereby the fuse 175 is interrupted. When the control circuit 133 turns on the transistors Ta and Tc, a current source current of +24 V flows through the resistor R 20 , the transistor Ta, the diode D 11 , the fuse 174 and the transistor Tc, whereby the fuse 174 is interrupted becomes.

If the control circuit 133 according to FIG. 16 determines that the fuses 176 and 174 are connected or intact, this confirms or determines that a new fixing unit 33 of the 100 V series has been inserted. If the control circuit 133 determines that only the fuse 174 is intact, this confirms that an "old" fusing unit 33 of the 100 V series has been inserted. If the control circuit 133 detects the connection of the fuses 176 and 175 , this confirms that a new fixing unit 33 of the 200 V series has been inserted. If the control circuit 133 determines or detects that only the fuse 175 is intact, it is confirmed that an old fusing unit 33 of the 200 V series is inserted. If the control circuit 133 does not determine that one of the fuses 174 , 175 and 176 is intact or only determines that the fuse 176 is intact, this indicates the end of the operating life of the fixing unit 33 or the need to replace it.

The initial operation of the image forming apparatus when it is turned on is described below with reference to the flowchart of FIG. 17. In a step S 1 , the power switch is closed, and the control circuit 133 reads in the control state of the input voltage changeover switch 70 . The voltage specification or specification of 100 V, 120 V or 220 V is then read in on the basis of the actuating state of the switch 70 . In a step S 2 , the control circuit 133 retrieves the state of the fuses 174-176 in the fixing unit 33 . In particular, the transistor Ta is turned off, the transistors Tb and Tc are turned on and the state of the fuses 174-176 is read out via the buffers 192-194 . In a step S 3 , the control circuit 133 compares the operating voltage of the image forming device with the voltage specification for the fixing unit 33 . If the operating voltage of the voltage specification for the fixing unit 33 is not adapted, the display circuit 134 provides a related display in a step S 4 , and the driver 152 is controlled to switch off the solid-state relay 165 . As a result, the heating lamp 40 is not supplied with an AC input voltage. In this way, inadmissible fixing or thermal melting of the fixing unit 33 due to the difference between the operating voltage for the image-forming device and the voltage specification of the fixing unit 33 can be prevented.

If the operating voltage of the image forming device is adapted to the voltage specification or specification of the fixing unit 33 , the control circuit 133 determines in a step S 5 on the basis of the switching or intact state of the fuse 174 whether the fixing unit is new or old. If the fixing unit 33 is new, the control circuit 133 clears the counter for lifespan monitoring of the fixing unit in the memory 153 in a step S 6 , and turns on the transistors Ta and Tb in the fuse determination circuit 173 . In the following step S 7 , the current source voltage of +24 V is applied to interrupt the "new / old" fuse 176 . In a step S 8 , the control circuit 133 determines whether the operating life fuse 174 , 175 has been interrupted. If this is the case, the display circuit 134 displays the expiry of the operating life of the fixing unit 33 in a step S 9 . If the fuse 176 has not been interrupted in step S 5 or S 7 , the control operation proceeds from step S 8 to a step S 10 . In this case, the count of the counter provided in the memory 153 for operating life monitoring of the fusing unit is read, and it is determined or determined whether the count exceeds the size of 80,000 at which the operating life of the fusing unit has expired. In the positive case (YES) 11, the transistors Ta and Tc turned on in a step S. This applies the +24 V power source voltage to break fuse 174 or 175 . Then, in step S 9 , the control circuit 133 causes the display circuit 134 to display the lapse of the operating life of the fixing unit 33 . Then, when the operating life of the fixing unit has not expired, the control circuit 133 ends this initial operation.

As described above, the operating voltage of the image forming device is compared with the voltage specification for the fixing unit 33 on the basis of the operating life via monitoring fuses 174 and 175 . If a fixing unit 33 with a different voltage specification is inadvertently inserted, there is no power supply, so that inadvertent fixing or thermal melting of the fixing unit 33 is avoided.

Furthermore, the fuse for determining the new / old state and the life determination fuses are provided in the fixing unit 33 . The operating life of the fixing unit 33 can thus be monitored simply and reliably. The monitoring method using two different types of fuses is applicable not only to the fusing unit, but also to a drum unit or a development unit, in which an operational life monitoring or a presetting or specification of the current or power specification is required.

The invention described above thus becomes a Imaging device created in the event of a malfunction incorrect setting of the operating voltage in the ratio to the input AC voltage is safely avoided.

Claims (6)

1. Image generating device, characterized by
a fixing unit ( 33 ) which serves to fix an image on a transmission medium or recording medium (P) and can be operated in a predetermined operating voltage range and is removably attached to a body or housing ( 1 ) of the device,
a unit ( 161 ) for supplying or supplying an output voltage to the fixing unit ( 33 ),
a unit ( 70 ) for designating or specifying the operating voltage range of the fixing unit ( 33 ) attached to the device body ( 1 ),
a unit ( 133 ) for determining whether the output voltage supplied by the supply unit ( 161 ) lies within the operating voltage range designated by the designation unit ( 70 ), in order to obtain a determination result and
a unit ( 68 ) which causes the supply unit ( 161 ) to supply the output voltage to the fixing unit ( 33 ) when the determination unit ( 133 ) has determined or has determined that the output voltage is within the specified operating voltage range. 2. Device according to claim 1, characterized by a unit ( 134 ) for displaying the determination result. 3. Apparatus according to claim 2, characterized in that the display unit display means ( 71 , 72 ) for displaying an output voltage lying outside the operating voltage range if the determination unit ( 133 ) has been true that the output voltage is outside the operating voltage range be designated. 4. Imaging device characterized by
a fixing unit ( 33 ) serving to fix an image on a transmission medium or recording medium (P), which has a (operational) life monitoring fuse unit ( 174-176 ) and which can be driven and removed from a body or in a predetermined operating voltage range Housing ( 1 ) of the device is attached,
a unit ( 70 ) for designating or specifying the predetermined operating voltage range of the fixing unit ( 33 ) attached to the device body ( 1 ),
a unit ( 161 ) for supplying or delivering an output signal representing an output voltage to the fixing unit ( 33 ),
a unit ( 133 ) for determining whether the output voltage represented by the output signal lies within the range of the operating voltage designated by the designation unit ( 70 ),
a unit ( 68 ) which has the supply unit ( 161 ) supply the output voltage to the fixing unit ( 33 ) when the determination unit ( 133 ) has determined or has ascertained that the output voltage is within the operating voltage range,
a unit (161) is to stop the supply of the output signal from the supply unit (161) when the output voltage outside the operating voltage range, and
a unit ( 133 , 173 ) for determining the remaining (operational) life of the fixing unit ( 33 ) based on a connection / disconnection or intact / - disconnection state of the life monitoring fuse unit ( 174-176 ) when the output voltage within the predetermined operating voltage range of the fixing unit ( 33 ). 5. Apparatus according to claim 4, characterized by a display device ( 71 , 72 ) for indicating that the output voltage is below the operating voltage range when the determination unit ( 133 , 173 ) has determined or has determined that the output voltage is below half the operating voltage range , or to indicate that the output voltage is above the operating voltage range when the determining unit ( 133 , 173 ) has determined or has determined that the output voltage is above the operating voltage range. 6. Apparatus according to claim 4, characterized in that the life monitoring fuse unit ( 174-176 ) a "new / old" fuse ( 176 ) to indicate whether the fixing unit ( 33 ) is new or old, and a (operating ) Lifetime fuse ( 174 , 175 ) to indicate the presence / absence of a remaining (operational) life of the fixing unit ( 33 ) and that the remaining life determination unit ( 133 , 173 ) has a "new" determination unit ( 133 ) for generating an output signal for determining that the fixing unit ( 33 ) is new when the "new / old" fuse ( 176 ) is not broken, a life counter ( 153 ) determined by the output signal from the "new" determination unit resettable, a unit ( 133 ) for detecting whether the life fuse ( 174 , 175 ) has been broken (when the "new / old" fuse ( 176 ) has been broken) and a unit ( 134 ) to indicate that the Operating life of the fuser has expired when the life fuse ( 174 , 176 ) has broken (and has been), and to detect whether the count of the life counter ( 153 ) has reached a predetermined size when the life fuse ( 174 , 175 ) has not been interrupted.